In daily work, we often hear the word "torque", so what is the torque of a motor?The moment that turns a mechanical element is called the rotational torque, or torque for short. Also known as torque. It is represented by the letter t and is measured in n·m (Nm).
Motor. In other words, the amount of rotational force.
Torque (torque in English).
The moment that turns a mechanical element is called the rotational torque, or torque for short. Mechanical components will produce a certain degree of torsional deformation under the action of torque, so torque is sometimes called torque. Torque is the basic load form of the transmission shaft of various working machinery, which is closely related to the working capacity, energy consumption, efficiency, operating life and safety performance of power machinery, and the measurement of torque is of great significance to the determination and control of the transmission shaft load, the strength design of the working parts of the transmission system and the selection of the capacity of the prime mover. In addition, the relationship between torque and power t=9549p n
The rated torque of the motor indicates the output torque at the end of the shaft of the motor under the rated conditions. Torque is equal to the product of force and force arm or force couple arm, in the International System of Units (SI), the unit of measurement of torque is Newton meters (n m), and kilograms of force meters and so on have been used as the unit of measurement of torque in engineering technology. The motor shaft end output torque is equal to the mechanical power output of the rotor divided by the mechanical angular velocity of the rotor.
Relationship with current: when the motor current is less than the rated current, the current is proportional to the torque, when the current exceeds the rated current, the core is magnetically saturated, the current increases, and the torque will not increase.
Relationship with power and speed: t = 9550 p n.
t: torque, nm;
p: power, kw;
n: rotational speed, r min;
9550 is the coefficient.
So how did this 9550 come about?It can be derived using formulas. Power = Force * Velocity.
That is: p = f * v torque = torque * radius of action.
That is: t=f*r, then f=tr, velocity=2 r*speed per second (n seconds).
Convert seconds to minutes: velocity=2 r*n 60 So: p=f*v=(t r)* 2 r*n 60)=2 tn 60
So launch: t=(p*60) (2 n).
2 is approximately equal to 628
So: t=955p/n
Note that here the unit of power p is w, and if you replace the unit p in the formula with kw, the formula becomes:
t=9550p/n
The formula for calculating the stalled torque of DC motor is tk=955keik 。
The torque formula of a three-phase asynchronous motor is:
s r2m=c u12 equation 2
r22+（s x20）2
c: is a constant related to the characteristics of the motor itself;u1: Input voltage ;r2 : rotor resistance;x20: rotor leakage inductance;s: slip rate.
It can be known that the torque of M U12 is proportional to the square of the power supply voltage, and the load torque is m2 when the normal input voltage is set, and the voltage drop makes the electromagnetic torque M drop a lotSince M2 is unchanged, the equilibrium relationship between M and M2 is destroyed, resulting in a decrease in the speed of the motor and an increase in the slip rateIt in turn causes a change in the rotor voltage balance equation, which causes the rotor current i2 to rise. That is, the stator current i1 increases accordingly (as can be known from the transformer relationship);At the same time, when i2 increases, the torque m sent from the motor shaft rises again until it is equal to m2. At this time, the speed of the motor tends to a new stable value.
Torque can be divided into static torque and dynamic torque.
Static torque is a torque whose value does not change with time or changes very little and very slowly, including resting torque, constant torque, slowly varying torque, and micro-ripple torque.
The value of the resting torque is constant, and the transmission shaft does not rotate;
The value of the constant torque is constant, but the transmission shaft rotates at a constant speed, such as the torque when the motor is working stably;
The value of the slow torque changes slowly over time, but the value of the torque can be considered constant for a short period of time
The instantaneous value of the micro-ripple torque has a small ripple variation.
Dynamic torque is the torque whose value varies greatly with time, including vibration torque, transition torque and random torque. The value of the vibration torque fluctuates periodically;Transition torque is the process of torque change when a machine transitions from one working condition to another;Random torque is an uncertain, irregularly variable torque.
Depending on the case of torque, different torque measurement methods can be taken.
Torque = 9550 * power speed.
Equally. Power = Rotational speed * Torque 9550
In the equilibrium equation: the unit of power (kw);Units of rotational speed (r min);The unit of torque (n.).m）；9550 is the calculation factor.